Momentum and spatial imaging of multi-fragment dissociation reactions

Abstract

We consider the measurement of multi-particle fragmentation of atomic and molecular systems in momentum space and to what extent such measurements allow the direct imaging of the spatial probability distribution of the fragments emerging from the interaction region. We present a simple derivation of the imaging theorem (IT) relating the asymptotic momentum distribution of the fragments to their spatial continuum wavefunction. We emphasize application to a real detector with finite momentum and spatial resolution. We also consider the role of particle-detector entanglement and decoherence in establishing the IT.